I reinstalled 7.20.2 x64 and got the same "SSL Connect Error," so I downgraded to 7.16.11 x64 and it appears to be working again. No issues with Internet connectivity (e.g. it tries to connect to https:// www. google .com) and I believe it connected successfully to WCG servers, but they're currently out of work.

I wanted to know the differences between the 7.16.x and 7.20.x branches, so the BOINC Release Notes state:



I assume this means "Use system's OS certificate bundle," which explains why downgrading back to 7.16 works, since before 7.20.x BOINC uses its own CA bundle at C:\Program Files\BOINC\ca-bundle.crt

The question then is what is missing (permissions or certs) in my copy of Windows 10 Pro 22H2 that is not allowing BOINC to access the Windows native CA certificate store. Either a Windows 10 bug or a BOINC bug.